In the case wherein a solid phase surface such as of glass material or a silicon substrate is chemically treated using certain molecules, a conventional technique as illustrated below is generally used wherein a solution where the molecules are dissolved in a solvent as a solute is utilized.
One example is a method for completely immersing the solid phase surface to be chemically processed in the above-described solution. In this case, the solid phase surface is chemically treated by means of molecules in the solution without having selectivity in terms of the location.
Another example is a method for drawing a predetermined pattern on a solid phase surface with the above-described solution being dispensed by a dispenser (apparatus for discharging a set amount of liquid). In this case, the solid phase surface is chemically treated with the above-described solute with locational selectivity. In accordance with this method using a dispenser, the fineness of the patterning can be increased to a certain extent by scaling down the diameter of the opening of the dispenser.
In the field of microfluidics, a technology using a tool referred to as a microfluidic probe or a micropipette is known as a technology for dispensing a microscopic amount of solution onto a solid phase surface.
Tools referred to as microfluidics probes have a flat surface, referred to as the mesa, formed at the end of a probe made of Si or the like and also have two openings created next to the mesa. These tools dispense a solution through one opening in a state wherein the mesa faces a solid phase surface in parallel and, at the same time, suction up the solution through the other opening so that the dispensed solution can be prevented from spreading, making it possible for the solution to stay in a narrow region (see Non-Patent Document 1).
Meanwhile, tools referred to as micropipettes have three openings aligned in a line in an end portion of a pipette made of polydimethylsiloxane (PDMS) or the like. There tools dispense a solution through the center opening and, at the same time, suction up the solution through the openings on the two sides so that the solution can be prevented from spreading over the solid phase surface in the same manner as described above (see Non-Patent Document 2).